help with dead 18650 battery

gglockner

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I purchased two green ncr 18650a protected batteries and a xtar wp2 charger. I might have changed out the batteries a couple of times, but for the most part I have been using the same battery and the other one sat parked in the charger. Did I ruin it by leaving it in the charger? It was not plugged in. I might have used the battery once for a USB charge. The voltage now reads .6 and the light goes green on the charger instead of red. Is there anything I can do besides go out and by another one?

Thanks,
Glen
 

LilKevin715

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Sounds like you killed the cell by allowing it to discharge on the charger after charging it. If the open circuit voltage is 0.6v then toss/recycle it, its not safe to use. Lesson learned...
 

gglockner

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Sounds like you killed the cell by allowing it to discharge on the charger after charging it. If the open circuit voltage is 0.6v then toss/recycle it, its not safe to use. Lesson learned...

I wouldn't think there would be any drain by leaving it in the charger. It is now up to 1.50v , after an hour or two plugged back into the charger. Still has the green light on the charger.
 

gglockner

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THE_dAY

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Your very welcome.
I've got a couple of 18650s coming in, my first ones and I've been doing a lot of reading up on them and that thread was still fresh in my mind.
I'm glad it worked out!
 

Norm

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. The voltage now reads .6 and the light goes green on the charger instead of red. Is there anything I can do besides go out and by another one?

Thanks,
Glen

You might have tripped the protection circuit, some good info on a fix here:

http://www.candlepowerforums.com/vb...dilast-18650&p=4053717&viewfull=1#post4053717

If your battery was reading .6 of a Volt the protection circuit was definitely not tripped. Batteries with tripped protection read 0 Volts.

Norm
 

moderator007

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When you used HKJ method you paralled the cells. The good battery may have actually charged up the bad battery to 2.0v. They try to equalize in parallel.
But I dont see why the pcb is not tripping at that voltage of 2.0v. Like norm says should be zero. I have not actually tested to see if the battery left in the charger does have some parasitic drain, but I have read many times it does.

I would think it would have to be left their for a month or more to actually drain a fully charged battery. If the charger was draining the battery at a rate of 1ma for a 2600mah cell it would take close to 2600 hrs to discharge it. But if it had a 10ma drain thats only 260hrs. 24hrs in a day so maybe 11 days. You could possibly test this with a DMM to see what the drain is. With one end of the battery contacting the charger terminal and the other end of the battery would have one DMM lead to the battery and the other lead to the other charger terminal. Set the DMM to current in amps or milliamps. Milliamps would be more accurate if the DMM has this setting.

If you do get the cell charged up, I would be interested in the results. Do be cautious and dont leave it unattended while charging.
 

THE_dAY

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If your battery was reading .6 of a Volt the protection circuit was definitely not tripped. Batteries with tripped protection read 0 Volts.

Norm
Thanks for this info.

So was it correct to use that method to "revive" the cell then start charging it?
Or should it have been tossed out?
 

Changchung

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Thanks for this info.

So was it correct to use that method to "revive" the cell then start charging it?
Or should it have been tossed out?

I dont think that you have to throw away the batt, you just revive it because the pcb protect the battery.

I always think that is not a good idea leave the batteries in the charger when it is not connected


Sent from my phone with camera with flash and internet on it... :D
 

THE_dAY

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I dont think that you have to throw away the batt, you just revive it because the pcb protect the battery.

I always think that is not a good idea leave the batteries in the charger when it is not connected


Sent from my phone with camera with flash and internet on it... :D

I wonder if the pcb on this one is faulty?
 

Changchung

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I think we've already established the protection didn't trip.

Norm

Sometimes that happen to some of batts and the multmeter read something like 0.06volts I use the revive method and the batt work just fine, this measurent dont mean that exist some volt out going of the pcb, it is just a electronic residue.


Sent from my phone with camera with flash and internet on it... :D
 

gglockner

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Your battery is ok, use it and test it.


I monitored the charging very cautiously. When it reached 4.0v pulled it off the charger and tested it. Working just fine now. That battery probably was left for about 2 1/2 months in the charger. So it seems it may have drained it. Thank you all for the great information. Hope it helps someone else out there before they throw their battery away.
 

Changchung

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I have four of those and four protected as well.

Yesterday the same happen to two of my sanyo 2600, I leave it in a charger so long with charger unplug, I revive it and their are working now...


Sent from my phone with camera with flash and internet on it... :D
 
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Verndog

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I have four of those and four protected as well.

Yesterday the same happen to two of my sanyo 2600, I leave it in a charger so long with charger unplug, I revive it and their are working now...


Sent from my phone with camera with flash and internet on it... :D

What kind of charger kills a battery when left in it? This should not happen IMO.
 
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